Boat planing and brake apparatus

ABSTRACT

Boat planing and brake apparatus having a fin connectable to a transom of a boat and adapted to be swung between a horizontal planing position and on inclined braking position, the fin having an undersurface concave about a longitudinal axis.

United States Patent Inventor William B. White 798 Lampson St., Victoria, British Columbia, Canada Applv No. 23,179

Filed Mar. 27, 1970 Patented Aug. 31, 1971 BOAT PLANING AND BRAKE APPARATUS 5 Claims, 5 Drawing Figs. 0.5. CI....- 114/665 P. Int. Cl

Field of Search l l4/66.5 P

[56] References Cited UNITED STATES PATENTS 3,124,094 3/1964 Braten 1 14/665 F 3,399,643 9/1968 Bennett i. H4/66.5 P

Primary Examiner-Andrew H. Farrell Att0rneyLyle G. Trorey PATENTEU M1631 IQYI 3.602178 sum 1 or 2 William B. whit Inv 0 Lyle G. rorey,

Ag nt PATENTED M1831 l97| sum 2 or 2 William 1%. white,

Inv I! by Lyle G. Trorcy,

Agent BOAT'PLANING AND BRAKE APPARATUS BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to an attachment for boats and more particularly to a fin apparatus which is adjustable to aid the boat to plane, or to serve as a drag or brake.

2. Prior Art Attachments which serve as trolling brakes for motor boats permitting a boat engine to run at a reduced speed while trolling, without unduly reducing motor speed and which can be adjusted to permit the boat plane at speeds lower than designed planing speeds. Heretofore usually have been constructed and arranged so as to be swingable about a beam axis fixed in elevation relative to the boat bottom.

Furthermore, attachments of prior art, in order effectively to aid the boat to plane have been of relatively large size and have, consequently, increased the effective area of the boat thus increasing resistance.

Most attachments of prior art have not effectively helped to stabilize the boat so as to reduce tendency to swing from side to side while planing.

SUMMARY OF THE INVENTION v The present invention provides a planing and brake apparatus'for boats. The apparatus can be adjusted between a downwardly inclined braking position and a horizontally planing position, but is also capable of being adjusted vertically so as to obtain optimum effectiveness regardless of the planing of the boatdraft varying with load.

The apparatus of the presentinvention also stabilizes the boat so as to reduce its tendency to yaw when. planing and,

furthermore, is constructed and arranged so asto have small wetted area.

The apparatus of the present invention, furthermore, is relatively inexpensive to manufacture easy to apply to a-boat and is simple to operate.

The apparatus of the present invention includes:

a fin having an undersurface concave about a longitudinal axis,

means for connecting the fin at a forward end to a transom DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view. of a portion of a boat with apparatus of the invention attached,

FIG. 2 is a stern view of the boat of FIG. 1,

FIG. 3 is an enlarged isometric view of theapparatus, a fin v being partially shown,

FIG. 4 is an enlarged partly sectioned plan of the tin, FIG. 5 isa front elevation of a fin.

DETAILED DESCRIPTION Figs. 1 and 2.

A portion of a boat has a stern transom 11 and'aplanin'g .bottom 12, an outboard motor- 13 being' secured centrally to the transom. Planing and brakeapparatus 14 of the invention is secured to the transom on opposite sides of the-motor 13. Each apparatus includes a tip 15 and'm'eans 16 for securing a forward end 17 of each fin to the transom adjacent the bottom 12 of the boat, the means 16 being constructed and arranged 'so that the fin can be swung about an axis, termed a beam axis,

which-extends perpendicular to a fore and aft axis of the boat so that the fin can be disposed between a planing position as shown in full outline at 15, in FIG. 1 in which it extends substantially parallel to the bottom of the boat and a braking position 151 shown in broken outline in which it is downwardly inclined from the bottom of the boat so as to serve as a drag reducing the speed of the boat without unduly reducing the speed of themotor.

Figs. 3, 4, and 5 FIGS. 3, 4, and 5, illustrate, in detail, the boat planing and brake apparatus 141 The means 16 for attaching the fin 15 to the transom includes a base plate 18 having a pair of parallel spaced apart tracks 19, the trackbeing provided with inwardly turned lips 20 and 20.1. The base plate has holes 21 in opposite side marginal portions so that the plate can be bolted to the transom 11 in such a position that the tracks 19, when viewed from the stern of the boat, extend vertically. The plate also has a central vertically extending row of holes 22. A carrier plate 23 having a centralflange 24 fits between the tracks 19 being restrained by the lips 20 and 20.1 to slide within the tracks. I

A thumb screw 25, in the carrier plate, can be passed through any one of the holes 22 so as to provide vertical adjustment of the carrier plate relative to the bottom of the boat.

The fin 15, see particularly FIGS. 4 and 5, is a thin metallic construction, symmetrical about a longitudinal axis 30 having a pair of flat portions 31 sloping downwards from the longitudinal axis and terminating in downwardly curved side edge portions 32-32, defining a concave undersurface 33. As best shown in FIG. 4 the flat portions 3131 are inclined from the horizontal at an angle A, typically about 20inclination between 15 and 30 being suitable.

' The fin also includes a longitudinally extending central T- shaped rib 35 having a vertical leg 36 and a cross piece 37. The fin,-including the rib and the base plate 18 can be extruded aluminum. 1

A forwardly opening slot 38 is formed in one of the flat portions 31 adjacent the leg 36, for receiving the flange 24. The fin is mounted on a pin 39 extending within the slot, passed both through the leg 36 of the rib and the flange, the pin being swedged at each end. A bolt 40 passes through the leg 36 and through a curved slot 41 in the flange 34, see FIG. 3, the bolt having a thumb screw 42, providing means for positioning the fin at a desired inclination. The crosspiece 37, as seen in FIGS. 3 and 5, is relieved at the forward end of the fin to provide clearance for the flange 24.

OPERATION The fin, it will be appreciated, can be easily and quickly adjusted by loosening the wingnut 42, rotating the fin to a desired position then retightening the wingnut.

The adjustable carrier plate 33 provides vertical adjustment of the fin, particularly in a planing position, so as to permit a boat operator to achieve optimum planing effectiveness according to load, speed and other conditions.

The concave undersurface of the fin inhibits lateral movement of water and, consequently, improves lift. The curved side edge portions 32-.32 act as guiding vanes to effect longitudinal stabilization at high speed.

What I claim is:

- 1. Boat planning and brake apparatus including a. a fin having an undersurface concave about a longitudinal axIs, I b. means for connecting one end of the fin to a transom of a boat, vc. said means being constructed and arranged to permit the fin to be disposed between a planing position in which'it is substantially parallel to the bottom of the boat and a braking position in which it inclines downwards.

2. Apparatus as claimed in claim'l, wherein the means (b) includes:

d. baseplate plate adapted to be secured to the transom, the

base plate having spaced parallel tracks. e. a carrier plate slideably mounted between the tracks,

f. means on the carrier plate engageable with a-base plate for releasably securing the carrier plate against movement,

g. a flange extending from the carrier plate,

h. means for swingably connecting the fin adjacent a forward end thereof.for swinging movement about a beam axis so as to permit the tin to be disposed in selected 

1. Boat planning and brake apparatus including a. a fin having an undersurface concave about a longitudinal axis, b. means for connecting one end of the fin to a transom of a boat, c. said means being constructed and arranged to permit the fin to be disposed between a planing position in which it is substantially parallel to the bottom of the boat and a braking position in which it inclines downwards.
 2. Apparatus as claimed in claim 1, wherein the means (b) includes: d. baseplate plate adapted to be secured to the transom, the base plate having spacEd parallel tracks. e. a carrier plate slideably mounted between the tracks, f. means on the carrier plate engageable with a base plate for releasably securing the carrier plate against movement, g. a flange extending from the carrier plate, h. means for swingably connecting the fin adjacent a forward end thereof for swinging movement about a beam axis so as to permit the fin to be disposed in selected inclined positions, i. means for releasably securing the fin against movement about said athwart ship axis.
 3. Apparatus as claimed in claim 1, wherein the fin is of thin sheet metal having flat side portions inclined downwards from the longitudinal axis of the fin, the side portions terminating in downwardly curved side edge portions.
 4. Apparatus as claimed in claim 3, wherein the flat side portions are inclined between 15* to 25* from the horizontal.
 5. Apparatus as claimed in claim 3, wherein the flat side portions are inclined at an angle of 20* from the horizontal. 